Scientists can determine the mass of subatomic particles that are built from quarks by looking at the particles’ energy and momentum in four-dimensional spacetime. One of the quantities that encode this information, called the trace anomaly, is linked to the fact that physical observables from high-energy experiments depend on the energy/momentum scales involved.
At a talk held at CERN this week, the ATLAS collaboration at the Large Hadron Collider (LHC) reported observing top quarks in collisions between lead ions, marking the first observation of this process in interactions between atomic nuclei.
Physicists have learned a lot about the makeup of the universe over the past century and have developed many theories to explain how everything works. Two of the biggest are Einstein’s theory of general relativity, which describes the visible or classical world, and quantum theory, which describes the quantum world.
But one thing physicists do not understand completely is gravity. They also do not know if it fits into general relativity or quantum physics. Figuring out what gravity is would go a long way toward the development of a grand unified theory of physics, which would tie the two fields together—one of the biggest goals in the physics world.
In this new research, the team has developed an idea for a so-called table-top experiment that could be used to show whether gravity is changed when measured—if so, that would give strong evidence that it is a quantum property.
Chirality is a property of some molecules, subatomic particles, living organisms and other physical or biological systems. This property entails a lack of mirror symmetry in these systems’ underlying structures.
A group of South Korean researchers has successfully developed an integrated quantum circuit chip using photons (light particles). It is a system capable of controlling eight photons using a photonic integrated-circuit chip. With this system, they can explore various quantum phenomena, such as multipartite entanglement resulting from the interaction of the photons.
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Scientific Reports — 3D printed microfluidic lab-on-a-chip device for fiber-based dual beam optical manipulation. The final 3D printed chip offers three key features, such as an optimized fiber channel design for precise alignment of optical fibers, an optically clear window to visualize the trapping region, and a sample channel which facilitates hydrodynamic focusing of samples. A square zig–zag structure incorporated in the sample channel increases the number of particles at the trapping site and focuses the cells and particles during experiments when operating the chip at low Reynolds number. To evaluate the performance of the device for optical manipulation, we implemented on-chip, fiber-based optical trapping of different-sized microscopic particles and performed trap stiffness measurements. In addition, optical stretching of MCF-7 cells was successfully accomplished for the purpose of studying the effects of a cytochalasin metabolite, pyrichalasin H, on cell elasticity. We observed distinct changes in the deformability of single cells treated with pyrichalasin H compared to untreated cells. These results demonstrate that 3D printed microfluidic lab-on-a-chip devices offer a cost-effective and customizable platform for applications in optical manipulation.
In the quest to uncover the fundamental particles and forces of nature, one of the critical challenges facing high-energy experiments at the Large Hadron Collider (LHC) is ensuring the quality of the vast amounts of data collected. To do this, data quality monitoring systems are in place for the various subdetectors of an experiment and they play an important role in checking the accuracy of the data.
The Higgs boson is often referred to as the “God particle” due to its crucial role in our understanding of the mass of elementary particles. Discovered in 2012, it remains at the forefront of many research endeavors in physics. Recently, researchers at the Max Planck Institute have made significant advances in measuring its interactions with other particles, opening up thrilling new possibilities for the future of science.
In the Standard Model of particle physics, the Higgs boson plays a key role in giving mass to particles. To fully grasp how this occurs, it’s important to revisit the concepts of the Higgs field and mechanism.
Think of the Higgs field as a sort of invisible network or mud that fills the entire universe. This field, teeming with Higgs bosons, is present everywhere, even in a vacuum. When a particle moves through this field, it interacts with it. The Higgs mechanism essentially explains how this interaction with the field endows particles with mass.
Now, scientists have not only cooled muons but also accelerated them in an experiment at the Japan Proton Accelerator Research Complex, or J-PARC, in Tokai. The muons reached a speed of about 4 percent the speed of light, or roughly 12,000 kilometers per second, researchers report October 15 at arXiv.org.
The scientists first sent the muons into an aerogel, a lightweight material that slowed the muons and created muonium, an atomlike combination of a positively charged muon and a negatively charged electron. Next, a laser stripped away the electrons, leaving behind cooled muons that electromagnetic fields then accelerated.
Muon colliders could generate higher energy collisions than machines that smash protons, which are themselves made up of smaller particles called quarks. Each proton’s energy is divvied up among its quarks, meaning only part of the energy goes into the collision. Muons have no smaller bits inside. And they’re preferable to electrons, which lose energy as they circle an accelerator. Muons aren’t as affected by that issue thanks to their larger mass.
“Solar system formation models using the new solar composition successfully reproduce the compositions of large Kuiper Belt objects (KBOs) and carbonaceous chondrite meteorites, in light of the newly returned Ryugu and Bennu asteroid samples from JAXA’s Hayabusa-2 and NASA’s OSIRIS-REx missions.”
To make this discovery, the team combined new measurements of solar neutrinos and data about the solar wind composition from NASA’s Genesis mission, together with the abundance of water found in primitive meteorites that originated in the outer solar system. They also used the densities of large KBOs such as Pluto and its moon Charon, as determined by NASA’s New Horizons mission.
“This work provides testable predictions for future helioseismology, solar neutrino and cosmochemical measurements, including future comet sample return missions,” Truong said.